1
|
Caumo S, Yera AB, Vicente A, Alves C, Roubicek DA, de Castro Vasconcellos P. Particulate matter-bound organic compounds: levels, mutagenicity, and health risks. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2022; 29:31293-31310. [PMID: 35001282 DOI: 10.1007/s11356-021-17965-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2021] [Accepted: 12/02/2021] [Indexed: 06/14/2023]
Abstract
Increased industrialization and consumption of fossil fuels in the Metropolitan Region of São Paulo (MRSP), Brazil, have caused a growth of the particulate matter emissions to the atmosphere and an increase in population health problems. Particulate and gaseous phase samples were collected in different short campaigns (2015, 2016, and 2017) near an urban-industrial area. Organic carbon (OC), elemental carbon (EC), polycyclic aromatic hydrocarbons (PAH), and its derivatives (nitro and oxy-PAH), n-alkanes, hopanes, and pesticides were determined. The Salmonella/microsome test confirmed the mutagenic activity of these samples. Among PAH, benzo(a)pyrene was detected as one of the most abundant compounds. Benzo(a)pyrene equivalent concentrations for PAH and nitro-PAH, and the associated risk of lung cancer, showed values above those recommended in the literature. The profile of n-alkanes confirmed the predominance of anthropogenic sources. Pesticide concentrations and estimated risks, such as the daily inhalation exposure and hazard quotient, suggest that exposure to these compounds in this area may be dangerous to human health.
Collapse
Affiliation(s)
- Sofia Caumo
- Institute of Chemistry, University of São Paulo, São Paulo, 05508-000, Brazil.
| | - Aleinnys B Yera
- Institute of Chemistry, University of São Paulo, São Paulo, 05508-000, Brazil
| | - Ana Vicente
- Centre for Environmental and Marine Studies, Department of Environment and Planning, University of Aveiro, 3810-193, Aveiro, Portugal
| | - Célia Alves
- Centre for Environmental and Marine Studies, Department of Environment and Planning, University of Aveiro, 3810-193, Aveiro, Portugal
| | - Deborah A Roubicek
- Dept. Environmental Analyses, São Paulo State Environmental Agency, CETESB, São Paulo, Brazil
| | | |
Collapse
|
2
|
Yadav IC, Devi NL, Li J, Zhang G. Altitudinal and spatial variations of polycyclic aromatic hydrocarbons in Nepal: Implications on source apportionment and risk assessment. CHEMOSPHERE 2018; 198:386-396. [PMID: 29421754 DOI: 10.1016/j.chemosphere.2018.01.075] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2017] [Revised: 01/15/2018] [Accepted: 01/15/2018] [Indexed: 06/08/2023]
Abstract
Although several global/regional studies have detailed the high level of polycyclic aromatic hydrocarbons in urban areas worldwide, unfortunately, Nepal has never been part of any global/regional regular monitoring plan. Despite few sporadic studies exist, the systematic monitoring and integrated concentration of PAHs in urban region of Nepal are lacking. In this study, the concentrations, sources, and health risk assessment of 16 PAHs in air (n = 34) were investigated in suspected source areas/more densely populated regions of Nepal. Four potential source areas in Nepal were focused as it was conjectured that urban centers in plain areas (Birgunj and Biratnagar) would possibly be more influenced by PAHs as a result of intense biomass/crop residue burning than those in hilly areas (Kathmandu and Pokhara). The overall concentrations of ∑16PAHs ranged from 4.3 to 131 ng/m3 (median 33.3 ng/m3). ∑16PAH concentrations in plain areas were two folds higher than those in hilly areas. PHE was the most abundant followed by FLUA, PYR, and NAP, which accounted for 36%, 15%, 12%, and 9% of ∑16PAHs, respectively. Principal component analysis confirmed that PAHs in highly urbanized areas (Kathmandu and Pokhara) were related to diesel exhausts and coal combustion, while PAHs in less urbanized regions (Birgunj and Biratnagar) originated from biomass and domestic wood combustions. Furthermore, in the urban areas of Nepal, vehicular emission could also influence atmospheric PAHs. The lifetime cancer risk per million populations due to PAH exposures was estimated to be higher for plain areas than that for hilly areas, suggesting a relatively greater risk of cancer in people living in plain areas.
Collapse
Affiliation(s)
- Ishwar Chandra Yadav
- State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, PR China; Department of International Environmental and Agricultural Science (IEAS), Tokyo University of Agriculture and Technology (TUAT) 3-5-8, Saiwai-Cho, Fuchu, Tokyo, 1838509, Japan.
| | | | - Jun Li
- State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, PR China
| | - Gan Zhang
- State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, PR China
| |
Collapse
|
3
|
Jadoon WA, Sakugawa H. Concentrations of polycyclic aromatic hydrocarbons: Their potential health risks and sources at three non-urban sites in Japan. JOURNAL OF ENVIRONMENTAL SCIENCE AND HEALTH. PART A, TOXIC/HAZARDOUS SUBSTANCES & ENVIRONMENTAL ENGINEERING 2016; 51:884-899. [PMID: 27314274 DOI: 10.1080/10934529.2016.1191300] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
This investigation was undertaken to monitor particulate polycyclic aromatic hydrocarbons (PAHs) concentrations in order to determine their emission sources and potential human health risks in remote and rural areas of Japan. Seventeen PAHs in aerosol samples collected in remote (Kamihaya), coastal (Hiki) and inland (Higashi-Hiroshima) areas of Japan during 2013-2014 were analyzed using gas chromatography/mass spectrometry. Total PAH (Σ17PAH) concentrations in aerosol samples were in the range of 0.08-6.51 ng m(-3), 0.09-4.74 ng m(-3), and 0.21-6.53 ng m(-3) at Kamihaya, Hiki, and Higashi-Hiroshima sites, with mean concentrations of 1.63, 1.18, and 2.43 ng m(-3), respectively. Significant seasonal variation in concentrations occurred at Hiki and Higashi-Hiroshima, while no significant variation occurred at Kamihaya. Ambient air temperature greatly affected PAH concentrations in Higashi-Hiroshima, but had only moderate effects in Kamihaya and Hiki. Wind direction also influenced the concentrations of PAHs. Vehicle exhaust, industrial emissions, biomass combustion, and domestic heating and cooking were identified as the main PAH emission sources using principal component analysis. Backward trajectory calculations showed that domestically generated PAHs were significant in Kamihaya and Hiki, while in Higashi-Hiroshima concentrations were mainly influenced by long-range transport. The incremental lifetime lung cancer risk had values of 3.38 × 10(-5) and 1.84 × 10(-5) at Higashi-Hiroshima and Hiki, which are greater than the US EPA acceptable level (10(-6)). Typically, 5-6-ring PAHs contributed 95% to this overall health risk, of which benzo(a)pyrene was the largest contributor, followed by dibenz(a,h)anthracene at both residential sites. Clearly, stricter guidelines for PAHs need to be implemented at these sites to protect the population.
Collapse
Affiliation(s)
- Waqar A Jadoon
- a Graduate School of Biosphere Science , Hiroshima University , Higashi Hiroshima , Japan
| | - Hiroshi Sakugawa
- a Graduate School of Biosphere Science , Hiroshima University , Higashi Hiroshima , Japan
| |
Collapse
|
4
|
Kim SK, Chae DH. Seasonal variation in diffusive exchange of polycyclic aromatic hydrocarbons across the air-seawater interface in coastal urban area. MARINE POLLUTION BULLETIN 2016; 109:221-229. [PMID: 27269384 DOI: 10.1016/j.marpolbul.2016.05.078] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2015] [Revised: 04/13/2016] [Accepted: 05/29/2016] [Indexed: 06/06/2023]
Abstract
Concentrations of 15 polycyclic aromatic hydrocarbons (PAHs) in air-seawater interface were measured over 1year in the coastal region of Incheon, South Korea. Most individual PAHs and total PAHs in air displayed statistically significant negative correlations with temperature, but not significant in seawater. Less hydrophobic compounds with three rings were at or near equilibrium in summer, while PAHs with four to six rings were in disequilibrium in all seasons, with higher fugacity gradients in colder seasons and for more hydrophobic compounds. Differently from fugacity gradients, the highest net fluxes occurred for some three- and four-ring PAHs showing the highest atmospheric concentrations. Net gaseous exchange, which was higher in winter, occurred from air to seawater with an annual cumulative flux of 2075μg/m(2)/year (for Σ15PAHs), indicating that atmospheric PAHs in this region, originating from coal/biomass combustion, can deteriorate the quality of seawater and sediment.
Collapse
Affiliation(s)
- Seung-Kyu Kim
- Department of Marine Science, College of Natural Sciences, Incheon National University, 119 Academy-ro (Songdo-dong), Yeonsu-gu, Incheon 22012, South Korea; Research Institute of Basic Sciences, Incheon National University, 119 Academy-ro (Songdo-dong), Yeonsu-gu, Incheon 22012, South Korea.
| | - Doo Hyun Chae
- Department of Biology, Incheon National University, 119 Academy-ro (Songdo-dong), Yeonsu-gu, Incheon 22012, South Korea
| |
Collapse
|
5
|
Hong WJ, Jia H, Ma WL, Sinha RK, Moon HB, Nakata H, Minh NH, Chi KH, Li WL, Kannan K, Sverko E, Li YF. Distribution, Fate, Inhalation Exposure and Lung Cancer Risk of Atmospheric Polycyclic Aromatic Hydrocarbons in Some Asian Countries. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2016; 50:7163-74. [PMID: 27268081 DOI: 10.1021/acs.est.6b01090] [Citation(s) in RCA: 96] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
A large-scale monitoring program, the Asia Soil and Air Monitoring Program (Asia-SAMP), was conducted in five Asian countries, including China, Japan, South Korea, Vietnam, and India. Air samples were collected using passive air samplers with polyurethane foam disks over four consecutive 3-month periods from September 2012 to August 2013 to measure the seasonal concentrations of 47 polycyclic aromatic hydrocarbons (PAHs), including 21 parent and 26 alkylated PAHs, at 176 sites (11 background, 83 rural, and 82 urban). The annual concentrations of total 47 PAHs (∑47PAHs) at all sites ranged from 6.29 to 688 ng/m(3) with median of 82.2 ng/m(3). Air concentrations of PAHs in China, Vietnam, and India were greater than those in Japan and South Korea. As expected, the air concentrations (ng/m(3)) were highest at urban sites (143 ± 117) followed by rural (126 ± 147) and background sites (22.4 ± 11.4). Significant positive correlations were found between PAH concentrations and atmosphere aerosol optical depth. The average benzo(a)pyrene equivalent concentration (BaPeq) was 5.61 ng/m(3). It was estimated that the annual BaPeq concentrations at 78.8% of the sampling sites exceeded the WHO guideline level. The mean population attributable fraction (PAF) for lung cancer due to inhalation exposure to outdoor PAHs was on the order 8.8‰ (0.056-52‰) for China, 0.38‰ (0.007-3.2‰) for Japan, 0.85‰ (0.042-4.5‰) for South Korea, 7.5‰ (0.26-27‰) for Vietnam, and 3.2‰ (0.047-20‰) for India. We estimated a number of lifetime excess lung cancer cases caused by exposure to PAHs, which the concentrations ranging from 27.8 to 2200, 1.36 to 108, 2.45 to 194, 21.8 to 1730, and 9.10 to 720 per million people for China, Japan, South Korea, Vietnam, and India, respectively. Overall, the lung cancer risk in China and Vietnam were higher than that in Japan, South Korea, and India.
Collapse
Affiliation(s)
- Wen-Jun Hong
- International Joint Research Center for Persistent Toxic Substances (IJRC-PTS), College of Environmental Science and Engineering, Dalian Maritime University , Dalian 116026, China
| | - Hongliang Jia
- International Joint Research Center for Persistent Toxic Substances (IJRC-PTS), College of Environmental Science and Engineering, Dalian Maritime University , Dalian 116026, China
| | - Wan-Li Ma
- IJRC-PTS, State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology , Harbin 150090, China
| | | | - Hyo-Bang Moon
- IJRC-PTS, Department of Marine Sciences and Convergent Technology, Hanyang University , 55 Hanyangdaehak-ro, Sangnok-gu, Ansan city, Gyeonggi-do 426-791, Republic of Korea
| | - Haruhiko Nakata
- IJRC-PTS, Graduate School of Science and Technology, Kumamoto University , 2-39-1 Kurokami, Kumamoto 860-8555, Japan
| | - Nguyen Hung Minh
- DIOXIN LABORATORY, Center for Environmental Monitoring (CEM), Vietnam Environmental Administration (VEA) , 556 Nguyen Van Cu, Long Bien, Ha Noi, Vietnam
| | - Kai Hsien Chi
- Institute of Environmental and Occupational Health Sciences, National Yang Ming University , Taipei 112, Taiwan
| | - Wen-Long Li
- IJRC-PTS, State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology , Harbin 150090, China
| | - Kurunthachalam Kannan
- IJRC-PTS, Wadsworth Center, New York State Department of Health, Department of Environmental Health Sciences, School of Public Health, State University of New York at Albany , Empire State Plaza, P.O. Box 509, Albany, New York 12201-0509, United States
| | - Ed Sverko
- IJRC-PTS, State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology , Harbin 150090, China
| | - Yi-Fan Li
- International Joint Research Center for Persistent Toxic Substances (IJRC-PTS), College of Environmental Science and Engineering, Dalian Maritime University , Dalian 116026, China
- IJRC-PTS, State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology , Harbin 150090, China
- IJRC-PTS-NA , Toronto, M2N 6X9, Canada
| |
Collapse
|
6
|
Ré N, Kataoka VMF, Cardoso CAL, Alcantara GB, de Souza JBG. Polycyclic aromatic hydrocarbon concentrations in gas and particle phases and source determination in atmospheric samples from a semiurban area of Dourados, Brazil. ARCHIVES OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY 2015; 69:69-80. [PMID: 25851064 DOI: 10.1007/s00244-015-0153-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2015] [Accepted: 03/13/2015] [Indexed: 06/04/2023]
Abstract
A headspace solid-phase microextraction (HS-SPME) procedure that employs a PDMS/DVB fiber was developed for the analysis of gas-phase polycyclic aromatic hydrocarbons (PAHs) collected in polyurethane foam (PUF) by gas chromatography (GC) mass spectrometry. The method exhibited good linearity (R (2) > 0.99) and repeatability (4.9-25 %) as well as an impressive detection limit that ranged from 1.1 to 3.3 ng. Twenty-two air samples were collected by high-volume samplers from January to November 2007 in a semiurban area of Dourados (Brazil) and were analyzed for their content of total suspended particulates and PAHs. The PAHs were extracted from the PUF samples using the developed procedure (HS-SPME), and PAHs adsorbed on particulate matter were extracted with dichloromethane/methanol (4:1 [v/v]) in an ultrasonic bath. The values of the total daily concentrations of 16 PAHs determined in the samples ranged from 0.375 to 8.407 ng m(-3). In addition, diagnostic ratios were calculated, showing that the PAHs in the atmosphere at the sampling site originated predominantly from vehicle emissions and the combustion of grass and wood. Hierarchical cluster analysis and principal component analysis were performed as well, the results of which indicated (1) the same sources of PAH identified by the diagnostic ratios and (2) that the sampling days could be categorized into three groups depending on the atmospheric conditions. GC retention indices were also used to identify PAHs, biphenyl (phenylbenzene), and heterocyclic organic compounds (benzofurans) in some of the samples.
Collapse
Affiliation(s)
- Nilva Ré
- Instituto de Química, Universidade Federal de Mato Grosso do Sul, Avenida Senador Filinto Muller, 1555, Campo Grande, MS, CEP 79074-460, Brazil,
| | | | | | | | | |
Collapse
|
7
|
Terzaghi E, Zacchello G, Scacchi M, Raspa G, Jones KC, Cerabolini B, Di Guardo A. Towards more ecologically realistic scenarios of plant uptake modelling for chemicals: PAHs in a small forest. THE SCIENCE OF THE TOTAL ENVIRONMENT 2015; 505:329-37. [PMID: 25461034 DOI: 10.1016/j.scitotenv.2014.09.108] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/19/2014] [Revised: 09/24/2014] [Accepted: 09/30/2014] [Indexed: 05/18/2023]
Abstract
The importance of plants in the accumulation of organic contaminants from air and soil was recognized to the point that even regulatory predictive approaches now include a vegetation compartment or sub-compartment. However, it has recently been shown that many of such approaches lack ecological realism to properly evaluate the dynamic of air/plant/soil exchange, especially when environmental conditions are subject to sudden variations of meteorological or ecological parameters. This paper focuses on the development of a fully dynamic scenario in which the variability of concentrations of selected chemicals in air and plant leaves was studied weekly and related to the corresponding meteorological and ecological parameters, to the evaluate their influence. To develop scenarios for modelling purposes, two different sampling campaigns were performed to measure temporal variability of: 1) polycyclic aromatic hydrocarbon (PAH) concentrations in air of a clearing and a forest site, as well as in leaves of two broadleaf species and 2) two important leaf and canopy traits, specific leaf area (SLA) and leaf area index (LAI). The aim was to evaluate in detail how the variability of meteorological and ecological parameters (SLA and LAI) can influence the uptake/release of organic contaminants by plants and therefore air concentrations. A principal component analysis demonstrated how both meteorological and ecological parameters jointly influence PAH air concentrations. SLA, LAI, as well as leaf density were showed to change over time and among species and to be directly proportional to leaf/canopy uptake rate. While hazelnut had the higher leaf uptake rate, maple became the most important species when considering the canopy uptake rate due to its higher LAI. Other species specific traits, such as the seasonal variation in production of new leaves and the timing of bud burst, were also shown to influence the uptake rate of PAHs by vegetation.
Collapse
Affiliation(s)
- Elisa Terzaghi
- Department of Science and High Technology, University of Insubria, Via Valleggio 11, 22100 Como, Italy; Department of Theoretical and Applied Sciences, University of Insubria, Via J. H. Dunant 3, 21100 Varese, Italy.
| | - Gabriele Zacchello
- Department of Science and High Technology, University of Insubria, Via Valleggio 11, 22100 Como, Italy
| | - Marco Scacchi
- Department of Science and High Technology, University of Insubria, Via Valleggio 11, 22100 Como, Italy
| | - Giuseppe Raspa
- Department of Chemical Engineering, Materials, and Environment, "La Sapienza" University, Via Eudossiana 18, 00184 Rome, Italy.
| | - Kevin C Jones
- Lancaster Environment Centre, Lancaster University, Lancaster LA1 4YQ, UK.
| | - Bruno Cerabolini
- Department of Theoretical and Applied Sciences, University of Insubria, Via J. H. Dunant 3, 21100 Varese, Italy.
| | - Antonio Di Guardo
- Department of Science and High Technology, University of Insubria, Via Valleggio 11, 22100 Como, Italy.
| |
Collapse
|
8
|
Lin Y, Qiu X, Ma Y, Ma J, Zheng M, Shao M. Concentrations and spatial distribution of polycyclic aromatic hydrocarbons (PAHs) and nitrated PAHs (NPAHs) in the atmosphere of North China, and the transformation from PAHs to NPAHs. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2015; 196:164-70. [PMID: 25463710 DOI: 10.1016/j.envpol.2014.10.005] [Citation(s) in RCA: 79] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2014] [Revised: 10/10/2014] [Accepted: 10/12/2014] [Indexed: 05/07/2023]
Abstract
The occurrence of polycyclic aromatic hydrocarbons (PAHs) and nitrated derivatives (NPAHs), as well as their transformation may have significant health impacts on humans. To investigate the level, spatial distribution and the transformation process of PAHs and NPAHs in North China, we performed a griddedfield passive air sampling campaign in summer of 2011. The median concentration of 25 PAH congeners and 13 NPAHs was 294 ng m(-3) (or 26.7 mg sample(-1)) and 203 ng sample(-1), respectively. Relative higher level of PAHs in Shanxi Province and NPAHs in megacities was observed. In North China, coal/biomass combustion and photochemical formation was the predominant source of PAHs and NPAHs, respectively.To investigate the relationship between these pollutants, a model incorporating NPAHs, PAHs and NO(2) was established, and the result indicated that NO(2) will promote the transformation processes from PAHs to NPAHs, which may increase the total toxicity of PAH-NPAH mixtures.
Collapse
Affiliation(s)
- Yan Lin
- State Key Joint Laboratory for Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Center for Environment and Health, Peking University, Beijing 100871, PR China
| | | | | | | | | | | |
Collapse
|
9
|
Kishida M. Distribution characteristics and source identification of polychlorinated dibenzo-p-dioxin and dibenzofurans, and dioxin-like polychlorinated biphenyls in the waters from River Kanzaki, running through Osaka urban area, Japan. J Environ Sci (China) 2013; 25:441-451. [PMID: 23923415 DOI: 10.1016/s1001-0742(12)60091-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
This is the first to elucidate the distribution and sources of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/PCDFs), and dioxin-like polychlorinated biphenyls in the waters from Kanzaki River, which is one of the most heavily polluted rivers in Japan. The World Health Organization (WHO)-toxic equivalent quantities (TEQs) in waters from the mainstream exceeded the Japanese environmental standard (1.0 pg-TEQ/L). The PCDD/PCDFs were dominated by highly chlorinated DFs, which predominantly contributed to the WHO-TEQs, suggesting that the main causes would be the incineration-related wastes. To find the sources, the dioxin congener concentrations in water and sediment samples from its tributary small waterways were determined. Abnormally high WHO-TEQs were detected in a water (50 pg-TEQ/L) and a sediment sample (41,000 ng-TEQ/kg dry weight) near the industrial solid waste incinerators (ISWIs). The PCDD/PCDF characteristics agreed well with those of the incinerator-related wastes as seen in the mainstream. These facts indicate that the dioxin pollution in the mainstream could be largely related to the industrial wastes from the ISWIs. Here, a TEQ apportionment method was used to understand the contribution of the pyrogenic sources to the WHO-TEQs. The average contribution ratios of the pyrogenic sources to WHO-TEQs were more than 80% for river waters from the mainstream, indicating that the elevated WHO-TEQs in the mainstream had been largely caused by the ISWIs.
Collapse
Affiliation(s)
- Masao Kishida
- Research Institute of Environment, Agriculture, and Fisheries, Osaka Prefecture, 1-3-62 Nakamichi, Higashinari-ku, Osaka 537-0025, Japan.
| |
Collapse
|